Chemical vapor deposition boron carbo–nitride deposited using dimethylamine borane with ammonia and ethylene

Abstract

Amorphous boron carbo–nitride films, BCxNy, (0.05⩽x⩽1.51,0.05⩽y⩽0.67), were deposited on SiO2 at 360°C and 1Torr using dimethylamine borane [NH(CH3)2:BH3] with ammonia and/or ethylene. The film composition could be controlled by varying the flow of ammonia and ethylene. X-ray photoelectron spectroscopy indicated a change in bonding environments, increasing the B–N bonding with the addition of ammonia and increasing B–C and C–C bonding with the addition of ethylene. The film dielectric constant, k, was 4.62 without coreactant, decreased to 4.11 by adding ammonia and 3.66 upon adding ethylene. The index of refraction ranged from 2.069 to 1.826 with correlation to k depending on the coreactant added. The root mean square surface roughness ranged from 0.30to0.65nm, increasing with the use of ethylene. A 1μm film deposited at 3.60°C using C2H4 had a hardness of 8.7GPa and modulus of 71.3GPa.